Printing telegraph apparatus



'July1 3 1943. ZENNER v 3, 59

PRINTING TELEGRAPH APPARATUS Filed April 18, 1941 1 INVENTOR WALTER .1. Z ENNER ATTOR N E-j Patented July 13, 1943 zszs sse PRINTING TELEGRAPH APPARATUS Walter-J.- Zenner, Des Plaines, Ill., assignor to Teletype Corporation, Chicago, 111., a corporation of Delaware Application April 18, 1941, Serial No. 389,147

7 Claims. (01.197 13) The present invention relates to printing telegraph apparatus and more particularly to compensating devices therefor.

The principal object of the invention is to provide a telegraph receiver which is capable of operating reliably and efficiently in any angular posi tion.

Another object of the invention is to provide in a tape telegraph receiver a platen shifting means which automatically compensates for gravitational efiects induced by changes in the angular position of the printing device.

Specifically, th arrangement according to the present invention provides for automatically adjusting the tension of the platen shift spring, so that when the printer is so positioned physically as to require the platen shift spring to lift the platen against the force of gravity, the tension or pull of the platen shift spring will be automatically increased to compensate for the increased load imposed thereon. Conversely, when the printer assumes a position so as to cause the platen to shift under the influence of both the platen shift spring and the force of gravity, the tension of said spring is automatically decreased to compensate for the assistance of the gravitational force in moving the platen.

The foregoing and other objects and features of the invention will appear from the following detailed description taken in conjunction with the accompanying drawing, in which,

Fig. 1 is a plan view of the tape printer, with certain parts broken away or removed to show other parts more clearly, showingthe compenating device of the present invention;

Fig. 2 is a partial elevational view showing the compensating device of the present invention;

Fig. 3 is a fragmentary perspective view taken substantially on line 3-3 of Fig. 1;

Fig. 4 is a sectional view taken on line 44 of Fig. 1; and

Fig. 5 is a fragmentary perspective vie taken substantially on line 5-5 of Fig.1.

Having reference to the drawing in which like reference characters indicate similarparts throughout the several views, the tape printing mechanism to which the compensating device according to the present invention is applied,is of the type disclosed in U. S. Patent No. 1,745,633, issued February 4, 1930 to S. Morton et al. Briefly, the selecting mechanism of the apparatus shown in Fig. 1 comprises a series of primary selectors or swords 12 arranged in superposed relation between spaced guide plates 13; which are mounted on studs l4 rising from a horizonta plate l6, which is supported in elevated position by a suitable bracket (not shown) rising'from the base'plate. The circular rear ends of the swords l2 pivotally engage corresponding seats in a series of bell crank levers H which are also arranged between the guide plates l3 and are pivoted on a stud I8. The other arms of the bell cranks I! are provided with pointed ends, and springs [9 'are provided to hold the bell cranks and swords 12 in their normal position with the pointed ends of the levers l1 adjacent the periph ery of a cam member 20. The cam member 20 is mounted upon the upper end of a shaft 2| driven bya motor 22, and; as it is rotated, a spirally disposed series of cam projectionsiil on the cam drum or member 20 are arranged tosuccessively oscillate the levers IT and reciprocate the swords l2.

In addition to their reciprocating movements, the swords 12 also may swing laterally about their pivotal connections with the lever I'l. 'The' piv otal movements of the swords l2 are limited by pins 26 projecting upwardly from the plate 'lfi and are controlled by the armature of an electromagnet 2'l. The magnet armature 23 is fixed to a lever 28-pivoted at 29 and limited in its vibratory movement by a pair of adjustable stop screws 30 and 3f. A spring 32 connected to the armatur lever and to an adjustable front screw 33 tends to hold the armature lever in engagement with the stop screw 31. The free T-shaped end of the armature lever 28 is provided with 'a pair of spaced depending lugs 35 and 42 which cooperate with pairs of laterally projecting arms 36 and 43 on the swords 12. The lugs 35 and 42 are so spaced that they will align with the contacting end of one or the other of the arm 3B and 43 of 'each sword l2, according as the controlling magnet 21 is energized or de-energized. In this way, the swords l2 are positioned in either their right-hand 'or left-hand position as they are reciprocated. The swords act through a series of T-levers 31 to position a set of longitudinally movable notched permutation bars 38. Bars 38 are arcuate in formiand are mounted on studs 39 which project upwardly from a fixed segmental plate 40 and extend through short slots 4| in the permutation bars to permit the IQhgltlldinal movement of each bar to either one of two positions. The springs l9 normally. urge sword 12 to their forward position in engagement with the T-levers 3T, and'the-permutation bars 38 are thereby held in one or the'other of said two positions, according to the'setting of the correspond ng swords in their right'or lefthand position.

Permutation bars 38 correspond in number to the number of selecting intervals of the code combinations or signals. As fully described in the aforementioned patent, the cam drum 20 is permitted to rotate upon receipt of a starting impulse which causes the de-energization of the magnet 21, thereby releasing the armature lever 28 which then responds to the pull of spring 32 to rotate the lever 28 in a clockwise direction. Upon this movement, an eccentric screw 34 cooperates with a plunger 24 which acts in the manner shown in Fig. of U. S. Patent No. 1,884,743,

to release, through a lever arrangement, a stop arm (not shown) to initiate rotation of cam 20.

The speed of rotation of selector cam drum is synchronized with the speed of code impulsing so that as the armature lever 28 is operated in respons to the received impulses, a cam acts upon its associated lever l! to rock it counterclockwise to bring its sword l2 against the selector lever 28. Swords 2 will be swung clockwise or counterclockwise, depending upon whether abutments 35 and 36 or 42 and 43 cooperate; for example, if abutments '35 and 36 cooperate, then the sword |2 will be swung in a clockwise direction and will assume the position shown in Fig. 1. On the other hand, if abutments 42 and 43 cooperate sword |2 wil1 be swung in a counterclockwise direction to assume the position opposite to that shown in Fig. 1. After the sword l2 has been set in accordance with the nature of the signal impulse and the cam drum 20 has rotated to bring a projection 25 out of cooperative engagement with lever I1, the lever I! will be actuated in a clockwise direction by its spring l9, carrying its associated sword |2 along with it to impinge the sword l2 against one or the other arm of the T-lever 31, thus rocking the T-lever in a counterclockwise or clockwise direction. Each of the T-levers 37 is pivotally articulated to a code bar 38 so that when a T-lever 31 is actuated in a clockwise or counterclockwise direction, its associated code bar is actuated leftwardly or rightwardly on studs 39. Accordingly, with the mechanism just described, the code bars 38 are set selectively in their rightward or leftward position in response to the impulses of a code signal.

The permutation bars 38 control a set of type bars 44 through the instrumentality of interconnected pull bars 45. As disclosed in the previously mentioned Patent 1,745,633, the pull bars 45 cooperate with aligned notches in the series of code bars, which, when found, permit the pull bar 45 to fall thereinto by means of its actuating spring (not shown) to bring an operating hook thereon into the path of a bail which is vertically reciprocable, as described in said patent. Upon the vertical movement of said bail, the pull bar is raised to cause the type bar 44 associated therewith to be pivoted downwardly to bring the type face thereon into contact with a circular platen 46. The type bar 44 is pivotally mounted in the segment 41 and is pivotally articulated to the pull bar 45 by a rack and pinion arrangement.

The paper tape upon which the characters are printed passes through a guide 48 mounted on a U-shaped bracket 5| and over the roller platen 46, the tape being held in engagement with the platen 46 by a pressure roller 49 that is connected to the platen by gears 52 and 53. A horizontal shaft 54 is rotatably and slidably mounted in front and rear brackets 55 and 56,

which project upwardly from the base plate l0, and extends through the arms of the U-shaped bracket 5| and through the roller platen 46. The platen 46 is keyed to the shaft 54 to rotate therewith, suitable feed mechanism (not shown) being provided for rotating the shaft 54 through gears 5'! and 58 thereby to rotate the platen 46 and advance the paper tape in a step by step manner.

Each of the type bars 44 is provided with two characters, a letters or lower case character and a figure or upper case character, and by axially shifting the shaft 54, bracket 5| and platen 46, the tape is positioned to receive the impact of either type face of the selected type bars. To guide the shift movement of the platen 46 and hold the bracket 5| against rotation, a horizontal member 59 projects rearwardly from the bracket 56 through an opening in the front arm of bracket 5|. Stop collar 6| adjustably mounted on the forward end of the shaft 54 and an adjustable stop screw 62 on the bracket 56 act to limit the shift movement of the platen 46.

The shift movement of platen 46 is eifected under the control of special pull bars 63 and 64 which are selectively controlled by the selector mechanism previously described, through the instrumentality of code bars 38. The platen 46 is shown in Figs. 1, 3 and 4 in the latched or letters position, wherein printing of lower case characters is effected. When the shift or figures pull bar 64 is selected, and is caused to be operated vertically by means of the previously mentioned operating bail (not shown) it operates through its lower horizontally extending portion to rotate a latching lever 65, pivoted on a bracket 66 mounted on base plate H), to disengage the forward end thereof from a latch 61 secured to the U-shaped bracket 5|. The latch lever is normally biased clockwise (as viewed in Fig. 3) by its spring 68. When the platen bracket 5| is thus unlatched, it is urged forwardly by its spring 69, one end of which is fastened to a bracket 7| secured to the bracket 5!, and the other end of which is fastened to one end of a lever 12 of the compensating device of the present invention.

When the letters or unshift pull bar 63 is selected in the manner shown and described in U. S. Patent 1,745,633 it is operated vertically by the operating bail (not shown). The lower end of the special pull bar 63 is provided with a horizontally extending portion which cooperates with one arm of a lever 13 pivoted on a bracket 14 mounted on the base plate 6. When the pull bar 63 is raised by the main operating bail after a previous unlatching operation by the figures pull bar 64, the pull bar 63 acts to rotate lever 13 clockwise (as viewed in Fig. 5) to cause arm 15 of lever 13 to cooperate with arm 16 of a shift rocker 11 (Fig. 4) pivotally mounted at 89 on a bracket 18 supported on base plate l0. Lever 13 is normally biased in a clockwise direction by a light spring 19 to maintain arm 15 thereof in cooperative relation with arm 76 of the rocker H. To render the relationship between arms 15 and 16 adjustable, the rocker 1'! comprises portion 16 and 86 both of which are mounted on pivot 89 and are adjustably related by means of a slot and screw adjustment 96. Portion Hi of rocker T1 is provided with a notch 8| by means of which it is articulated to the extension bracket 1|. Thus when the pull bar 63 is raised to rotate lever 13 in a clockwise direction to impart counterclockwise rotation to rocker 11 (Fig. 4) the platen bracket through the articulation of its extension bracket H with notch BI will be urged inwardly (Fig. 1) or leftwardly (as shown in Fig. 4) against the tension of the platen operating spring 69.

In accordance with the present invention, a mechanism is provided for compensating or adjusting the tension of spring 69 automatically upon changes in physical position of the printing apparatus. This change is efiected irrespective of the physical positionment of the apparatus or change in physical position of the assembly as a whole with respect to gravity. The compensating device of the present invention comprises the above-mentioned lever 12 which is pivotally supported on a bracket 85 mounted on the base plate II]. A counterweight 86 is secured to the left-hand arm of the lever 12, and adjacent the counterweight 86 there is secured to the arm of lever 12 one end of a spring 81 the other end of which is fixed to a spring post 88 mounted in the base plate [0.

Thus, if the apparatus shown in Fig. 1 is considered as being positioned with the shaft 54 disposed vertically, with the bracket 56 lowermost, and with the platen bracket 5| maintained latched by the co-engagement of the lever 65 with looking toe 61, the tension of spring 69 will be automatically reduced by the counterclockwise rocking of lever 12 due to the efiect of gravity upon the counterweight 86, moving the counterweight 85 in the direction as exemplified by the dotted line 9| against the tension of spring 81. Then, when the platen bracket 5| is unlatched under the control of the figures shift pull bar 64, the

platen bracket 5|, together with platen 46, will respond to the pull of gravity as well as the reduced tension of spring 69 and fall against the stop 62.

On the other hand, if it is assumed that the apparatus shown in Fig. 1 is positioned in an opposite manner, with its shaft 54 vertical, but with the bracket 55 lowermost, and the bracket 5| latched by the co-engagement of its toe 61 with lever 65, then, when the platen bracket 5! is unlatched under the control of the figures shift pull bar 64, the platen bracket 5!, together with the platen 5 will respond to the pull of the spring 69 and. be drawn against the stop 62. However, under these conditions, the spring 69 will have had its tension increased automatically by the rocking of lever 12 clockwise due to the effect of gravity on the counterweight 86 and the pull of spring 81, moving the counterweight 86 in a direction as exemplified by the dotted line 92. Thus tensioned, the spring 69 will function to raise the platen 4'5 and bracket 51 up to the stop 62 against the force of gravity.

It is contemplated that the mass of the counterweight B6 and the strength of the sprin s 69 and 8'! are so chosen a to give the most eilicient counterbalancing and automatic adjusting effect under existing operating conditions.

Although the present invention has been disclosed in connection with a certain specific embodiment thereof, it is understood that the embodiment shown is given only by way of illustration, and that all forms coming within the scope of equivalency of the appended claims are intended to be covered herein- What is claimed is:

1. In a printing device, a platen, driving means for shifting said platen from a first case position to a second case position, power storage means for shifting said platen from said second case position to said first case position, and weighted means efiective automatically to vary the power stored in said power storage means whereby said power storage means is effective irrespective of change in physical position of the printing device with respect to gravity without diminishing the effectiveness of said driving means.

2. In a printing device, a movable carriage, spring means for moving said carriage, and gravity-responsive counterbalancing means effective directly on said spring means to vary the power stored therein, whereby the effect of gravity upon said carriage is compensated for automatically irrespective of change in physical position of the printing device with respect to gravity.

3. In a printing device, a movable carriage, spring means for moving said carriage, and gravity-responsive counterbalaneing means for automatically varying the tension of said spring means for compensating for the efiect of gravity upon said carriage irrespective of change in physical pmition of the printing device with respect to gravity.

4. In printing device, a platen, driving means for shifting said platen in one direction, spring means for shifting said platen in an opposite direction, and gravity responsive counterbalancing means effective automatically on said spring means to vary the tension of said spring means whereby said spring means is effective irrespective of change in physical position of the printing device with respect to gravity without diminishing the efiectiveness of said driving means.

5. In a printing device, a platen, driving means for shifting said platen in one direction, means for shifting said platen in the opposite direction, means for latching said platen against operation by said spring means, and gravity responsive counterbalancing means effective on said spring means to vary the power stored therein, whereby the effect of gravity upon said platen when unlatched for operation is compensated for automatically irrespective of change in physical position of the printing device with respect to gravity.

6. In a printing device, a platen carriage, spring means for shifting said platen carriage from one position to another, and gravity-responsive means automatically operable to vary the tension of said spring means in response to positional changes of the-whole device.

7. In a printing device, a platen carriage, spring means for shifting said platen carriage from one position to another, and gravity-responsive means automatically operable to vary the tension of said spring means in accordance with variations in gravitational effects on said platen due to changes in position of the device as a whole.

WALTER J. ZENNER. 

